Catalytic combustion systems are well known in gas turbine applications to reduce the creation of pollutants in the combustion process. A typical gas turbine includes a compressor for compressing air, a combustion stage for producing a hot gas by burning fuel in the presence of the compressed air produced by the compressor, and a turbine for expanding the hot gas to extract shaft power. A catalytic combustion process may include premixing fuel with a portion of compressed air, and then partially oxidizing the resulting fuel/air mixture in the presence of a catalytic agent before passing the fuel/air mixture into the combustion stage. In some catalytic oxidation systems, a cooling scheme may be provided to control the temperature within the catalytic portion of the system to avoid temperature-induced failure of the catalyst and support structure materials. Cooling in such catalytic oxidation systems may be accomplished by using a technique known as backside cooling that includes passing a cooling agent over a backside of a catalyst-coated material.
U.S. Pat. No. 6,174,159 describes a catalytic oxidation method and apparatus for a gas turbine utilizing a backside cooled design. Multiple cooling conduits, such as tubes, are coated on the outside diameter with a catalytic material and are supported in a catalytic reactor module. A first portion of a fuel/air mixture is passed over the catalyst coated cooling conduits and is exothermically reacted, while simultaneously, a second portion of the fuel/air mixture enters the multiple cooling conduits and cools the catalyst. The exothermally catalyzed first portion then exits the catalytic oxidation system and is mixed with the second portion outside the system, creating a heated, partially combusted mixture.